Late Quaternary tephrochronology of Sweden: a review

摘要

Studies of Late Quaternary sediments in south and central Sweden have yielded a detailed tephrochronology for the Last Glacial-Interglacial transition (LGIT; ca, 15,000-10,000 cal. yr BP) and the Holocene. More than ten tephra layers have been detected and geochemically characterised. The most widespread tephra from the LGIT is the rhyolitic phase of the Vedde Ash (ca. 12,000 cal. yr BP) which has been found in lacustrine sediments and marine clays south of the Younger Dryas moraines in south Sweden. Other horizons from the LGIT identified to date include the Borrobol tephra (ca, 14,400 cal. yr BP), the Haesseldalen tephra (ca. 11,500 cal. yr BP), the 10-ka Askja tephra (ca. 11,300 cal. yr BP) and the Hoegstorpsmossen tephra (ca. 10,200 cal. yr BP). The most significant Holocene isochrones are Hekla-4 (ca. 4260 cal. yr BP), Hekla-Selsund/Kebister (ca. 3750 cal. yr BP), Hekla-3 (ca. 3000 cal. yr BP) and Askja-1875. Two new Late Holocene tephra horizons (the Stoemyren tephra, ca. 2100 cal. yr BP and the Gullbergby tephra; ca. 2700 cal. yr BP) were identified in single sites and are so far less valuable as marker horizons, but are potentially important for the future.